Earlier quoted context omitted.
Yes, thats true. But creating mp4 files with TeamViewer requires quite a bit codec installing and resulting file can be either enormous file size or lacks audio etc. If you want to challenge this, try to create reasonable mp4 file with TeamViewer :) edit just to add that Mac OS version of TeamViewer does not have conversion feature at all.
However, once one comes up with a suitable ffmpeg command line, it is literally one click to do the conversion locally. No need to upload something, not even to wait or to pay.
Handbrake for those that are CLI impaired. I've gotten great results with ffmpeg and use it often to share videos